Patient navigation (PN) is a community-centered approach that can potentially reduce health disparities by enhancing access to care at an earlier stage of the disease continuum for underserved populations, such as racial/ethnic minorities or individuals with low socioeconomic status. To date there are two large-scale federally-funded programs that involve PN interventions;one is the patient navigation research program sponsored by the National Cancer Institute (NCI);the other is a series of demonstration projects supported by Centers for Medicare and Medicaid Services (CMS). The NCI-sponsored sites mostly initiate PN services at the time an abnormal screening result is detected, whereas the CMS- sponsored sites attempt to engage PN services at an earlier stage so as to increase the uptake of cancer screening. Little is known about the cost-effectiveness of PN compared to usual care (UC) for either type of PN services. The objective of the proposed study is to develop a comprehensive research framework to assess the cost-effectiveness of a PN program targeted at various points in the continuum of cancer care - screening, diagnosis, and treatment. The study has three specific aims: (1) to evaluate the cost-effectiveness between usual care and patient navigation started at the time that an abnormal screening result was detected;(2) to compare the cost-effectiveness between usual care and patient navigation targeted at improving the uptake of cancer screening;and (3) to assess the cost-effectiveness between patient navigation programs initiated at various time points of the cancer care continuum. The study will utilize databases developed from the CMS demonstration site at University of Texas M.D. Anderson Cancer Center, supplemented with Medicare claims and information obtained from the literature, to evaluate the short-term and long-term cost-effectiveness of PN versus UC. Study perspective will include that of society, payors, and health care providers that employ patient navigators to facilitate services for their patients or the at-risk population in the surrounding neighborhood. We will employ appropriate statistical methods of cost-effectiveness analyses using patient-level data in the short-term analysis and will develop cancer-specific Markov models to assess the long-term cost-effectiveness. Findings from the proposed study will inform policy makers on the costs, comparative effectiveness, and cost-effectiveness of PN versus UC initiated at various time points of the cancer care continuum, as well as the comparison between PN services started at different time points. In addition, a user-friendly model will be developed for the study of the cost- effectiveness of PN;the model will be available to other intervention sites of PN services upon request. Patient navigation is a community-centered approach that can potentially reduce health disparities by enhancing access to care at an earlier disease stage for underserved populations. This study will develop a comprehensive and user-friendly model to compare the cost-effectiveness of patient navigation and usual care for navigation services initiated at different time points of the cancer care continuum. We will address both short-term and long- term cost-effectiveness PN services from three different interest groups: societal as a whole, insurance payors, and health care providers.